Assigrkoe



Oct. 30, 1928. 1,689,805

E. w. STEVENS PNEUMATI C HAMMER Filed July 30, 1926 HHI'II INVENTOR. L5H Z Edward 14/. vevens Peitented Oct. 30, 19238.

TOOL commuter, on New YL mi? it Application filed Juy 3D, 1926. SCTiEi]. 125 835 This invention reiates to fluid pi ossm'e poi- Q e tooiiif White ('OBCQ'ZDS tooleoi the deer ged type in which the lit/ i 78 fluid is at least p ny eontpolieci by an mitonmtienMy thrown naive and relates pei'tieniefly to the In order to illust 'g te ti'ie invention one eone i te enibo .iment tn eofi's shown in the aceta ay-111 ;;i1-;i m1 s, wi;16h;

igl 1 a lon 'ftndinqi 9 one-i View thi ongh z fluid p ei v e tool; "and (Fig. Qisnview similar to Fig. 1 showing 11 'e pill-ts in a different position.

:iie inye tion agiilnfstrated is embodied in t Qneninetie QGTCQSEiYG tool i121 Vin g 2 cylintier f3 piiovilding e pleton chz n'ibei' inn wh ch i913oceteis :1. ha nnnr piston 5 in'ipzu'ting w to a Woi king tool 6; Finch as a drill il'lpoifted in :(1 :fjront need or ohueik teetly 01. though an ii eii'inediete Ch jesnnvij block 8 which may be o b i'in ine'n'iiiei' 9 intei'po between cyi'inde 3 and gi'iront heedi'. Pi,- to n 5 ns an inte z'ig nch;nni1 e1"0y bore '10 J end (it the piston cinnne-igi tiy reiineed QPGE'iliip; o1.- i The rear end oi? the pnston V "'QWiliGii may be enlarged :uijzieent its enii bfy an ainnnier g 'ooye i5; sealed bye (fiOSllJfQIIIQRiiJQI' i" a head o1. cup poi'tion l1 Whicii p: k i f ee within the piston el ia'inl e and lies on integral plng ex tension i, in ll KPlQJL CiLHF EI ax ally mi n tnoplelid coopei ziting with the bore tinno iely to the interioi of the W "tension 11, alt-o hes its enter" 1' reduced as indjienteciat 11 to permit motive fluid ti oni bore the piet on to pose to ti'ie ree i' end ot the n "1e piston is in i ecl in Fig. 2.

3 which i eg'is ters with the cyl nder walls, which po upon the i ginfn n ttl 0 tm: :stroke and. aet ng vaii'e Tito jniove it to th Position ehown in nlready in that position,

wees

on To CHICAGO in on new Jnieenm rmeqnio :nimvixv nn.

Till e hezui oi the closure member may be nn iloi'oiit zinnnleriy as: indicated tit 11 to form n cijlfiilipli QIniini e or pocket for the leer 011%] of the piston. i i

lvhe admission of ino ti e fluid to the il'ont Ql1 oi the piston"ehmn her tobe operative nganist the i 'nt on of the piston the rearward sti'o o'if t'ne in er is controlled by {1D annular 1" o groove 12 in the piston cross po ts 13 and 14: in

ts connect re- 81). tiveiy with live oilpassage 13 and paesnge l t" Wine-h opens into the extreme front end of the pieton' eiizin'ibei' tiii'ougiii port 14L. The piston 21 o co nti'ols main exhaust ports If and "16 for the fear and iront en( s of the piston ohainbe respectively.

A valve li' 'z i'i'nngeii tobe controlled by the piston has lnnehto '(io ith in ogiiei' tune tionin of thehaimnei'. iThei aive is thrown to the -ez wa fl ioeition indicated iniiiig. 1 ion oi inoti e fiuid to passage whih inotiv fliiigi beconie dire tly eii'izo die fi'ont endotthe m e. The re ieth 'own to the fotwei'di position shown in Fig. on edlitii 'sion of the nlotii' e fluid to the oppo en of the vitoifeiiambef by 1i"? jii'oniiiiee "or the n'oioi ration of the iii'ni sion ()tinotive fluid Lo in i V ont enei of ti laten cinnnben ii i'liio iin i1. nuigir gi'ooyo 12m in the vniveeifi-ei'lizgedio cooperate on the one end ix ith ventQO kind on tiio'dtheir ivitii n pie "1 eontfolled passinge E21 opening: into the pi ton ohninbel" in 'spiited 1' ajtion to tiie re; iiansn imtiie i eni' end o'f the piston chamber.

The cycle of operation is as follows: Upon opex'iing g the nmnueily Cont oiled throttle iflheQQ inbztek heiid 23 iTlOQhG i iiiitiis wilniitted tolive Hi1 passage iiai ingi 81101163 eo nnecting inim 11 gindfpiie ii.

the parts are in the position I 1, the nio tii e fliiitti'l'ogil Hose "i? it is 1 I the p s on #110 i io i i t the motiye the movement of the latter.

fluid continues to pass to the front of the piston chamber since port 19 is still open, thus prolonging the admission of motive fluid until ports 13 and 19 are closed by the piston whereupon the rearward movement of piston 5 continues by expansion of the motive fluid. The opposite end of the piston chamber is open to exhaust through main e);- iause port 15 and after the latter is closed by the piston, the trapped air continues to escape through the auxiliary vent formed by pas sage 21, groove 17 in valve 17, and vent 20. Soonafter passage 21 is'closed by piston 5, the reduced internal bore 10 of the piston registers with the reduced portion 11 of extension 11 whereupon motive fluid continuously admitted to the interior of the piston passes to the rear end of the piston chamberto become effective against the rear end of the piston to assist the constant pressure area Within the piston to stop and to reverse Some of the motive fluid admitted to the rear end of the piston chamber is effective through passage 18 against the valve to throw it to the position shown in Fig. 2, the front end of the piston chamber being at this time open to exhaust through port 16. When the valve shifts it closes prolongation port 19 and breaks the connection between passage 21 and vent 20. The movement of the piston now reversed, and it moves forward to strike itsblow under-the impulse oflive motive fluid acting upon its interior pressure area and upon its rear end. Admission ofmotive fluid to the rear end of the piston chamber is shortly closed by the registering of the reduced bore 10 with the unreduced portion of extension 11 whereupon the pressure of the. expanding motive fluid previously ad mitted is now effective against the rear end of the piston. As the piston strikes its blow main exhaust port 15 is uncovered relieving the pressure in the rear end of the piston chamber, while at the same time ports 13 and 1% are again connected by the piston groove 12 to admit air to the front end of the piston chamber and to throw the valve to the position shown in Fig. 1, thus completing the cycle.

From the above it will be apparent that the present invention provides a fluid pressure hammer having an internal continuous pressure area and intermittent end areas controlled by the piston with. a valve arranged to be thrown on admission of motive fluid to the said intermittentpressure areas of the piston, that means are provided jointly under control of the piston and of the valve for prolonging the admission of motive fluid to one intermitte-ntarea of the piston and for providing an auxiliary exhaust for the opposite intermittent area, andthat the structure of hammers of this type is improved and the cost of manufacture and assembly lowered said irhamber and having an internal bore, the end wall. of said bore forming a PJ'GFSSUITQ area for driving the pie ton forwardly, a fixed member extending axially into said piston chamber and into said here to admit motive .l'luid cimtinuously to id area, piston controlled means for inte iuittcntl feeding and venting motive fluid to the ends of the piston, an automatic valve controlled by said piston for prolong ing the feeding of motive fluid to one end area of the piston and for priiividing an au 1- iliary exhaust for the other end area, and

means utilizingmotive fluid from the internal bore of said piston for moving the valve in one direction.

2. A fluid pressure tool comprising a cylinder providing a piston chamber, a piston reciprocable in said chamber and having an internal bore, the end. wall of said bore forming a pressure area for driving the piston forwardly, a fixed member extending axially into said piston chamber and into said bore to admit motive lluid continuously to said area, piston controlled means for intermittently feeding and venting motive fluid to the ends of the piston, a val ve coutrolled by said piston, means controlled by said valve for prolonging the feeding of motive fluid to the return end area of the piston while providing an auxiliary exhaust for the opposed end area of the piston in one position and for closure, both said means when in another positirm, and means utilizing motive fluid from the internal bore of said piston for n'ioving said valve in one direction and motive fluid from a separate supplv pass g0 controlled by said piston for the re 0 movement of said valve.

3. A fluid prersurc tool toniprisiug :1 cyl' inder providin a piston chamber, a piston reciprocable in said chamber and having an internal bore, the end wall of said here forming a pressure area for driving the piston forward y. a fixed member extending axially into said piston chamber and into said bore to admit motive fluid continuously to said area, cooperating means on said member and said piston permitting); motive fluid to pass to the adjacent end of the ]')l$i't)2i chamber lo act against the end area of the piston in one position of the latter, a valve controlled by said piston, said cylinder providing an exw in:

to an 10 n of motive fluid i whereby said e fluid adnntced valve is shifted by the motiv .id last named area.

41. it fluid pressure tool comprising a cylinder providing a piston chamber, a piston irocz ible in said chaml'ier and having; an in irnal bore, the end Wall of said bore forming a pi" u area for driviitig the piston forv ardly, a l d member extending axially into said p on chamber and into said bore to admit motive fluid continuously to said area, cooperating means on said member and said piston permitting motive fluid to pass to the adjacent end of the piston chamber to be effective against the end area of the piston in one position of the latter, a valve controlled by said piston, an auxiliary exhaust for said end of the piston chamber controlled both by said valve and said piston and effective immediately prior to the admission of motive fluid to said end area, and means whereby said valve is shifted by the motive fluid adn'iitted to said last named area, piston controlled. means for admitting motive fluid to the frontend of the piston chain ier to be effective againfit the front end of the piston for the return stroke of the latter, and means controlled jointly by said piston and by said valve for effecting a limited prolon ition of the admission of motive fluid to said front end.

A. fluid pressure tool comprising a cylinder prrn 'iding a piston chamber, a piston reciprocablc in said chamber and having an internal bare, the end Wall of said bore fornr ing' a pressure area for driving the piston for- \vardly, a lived member extending axially into srd pier n chamber and into said bore to admit motive fluid continumisly to said area, said member having a reduced portion to permit motive fluid to pass from said bore to the adjacc end of the chamber to be effective against the rear end of the piston, pisttui controlled means for admitting motive fluid to the fr it end of the chamber to be effective against. the front end of the piston for the return stroke of the later, a valve controlled by said piston, ,nd means controlled by said valve for providing an iliary exhaust for ti o rear end of said n and for prolonging; the admission of m ive fluid to the IlODt end of the piston .l .nber.

6. A fluid pressure tool compr'sing a cylinder providing a piston chamber, a piston rec-iprocable in said chamber and having an internal bore, the end vvall of said bore forming a pressure area for driving the piston for- Wardly, a fixed member cxtcn ding axially into said piston chamber and into said here to admitm-otive fluid continuously to said area, said member having a redi red portion to permit motive fluid to pass from said bore to the adjacent end of the chan'iber to be effective against the rear end of the piston, piston controlled means for admittinp motive tliuidf to the front end of the chamber to be effective against the front end of the piston for the rellll'llSlZl'OliO of the latter, a valve, said valve being shil ed in opposite directions on admission of motive fluid to the ends of the p on CllttllllJGl, and means controlled by said valve for venting one end of he piston chamber prior to the adu'iiss ion of motive fluid thereto and for prolonging the admission of motive fluid to the other end.

7. A fluid pressure tool comprising a cylinder providing a piston chamber, a piston reciprocable in said chamber andhaving an internal bore, the end Wall of said here forming a pressure area for driving the piston for wardly, a fixed member extending axially into said piston chamber and into said here to admit motive fluid continuously to said area, said member having a reduced portion to permit motive fluid to pass from said bore to the adjacent end of the chamber to be ef fective against the rear end of the piston, piston controlled means for admitting motive fluid to the frontend of the chamber to be effective against the front end of the piston for the return stroke of the latter, a valve, said valve being shifted in opposite directions on admission of motive fluid to the ends of the piston chamber, and means controlled by said valve for venting one end of the piston chamber prior to the admission of motive fluid thereto and for prolonging the admission of motive fluid to the other end, said means being operative in one position of the valve and inoperative in another position of the valve.

55. A fluid pressure tool comprising a cylinder providing a piston chamber, a. p. reciprocable in said chamber and having an internal bore, the end Wall of said bore forming a pressure area for driving the piston forwardly, a fixed member exten ding; axially into said piston chamber and into said bore to admit motive fluid continuously to said area, said member having a reduced portion to pernrit motive fluid to pass from said bore to the adjacent end of the chamber to be effective againstthe rear end of the piston, piston controlled means for admitting motive fluid to the front end of the chamber to be effective against the front end of the piston for the re turn stroke of the latter, a valve, said valve being shifted in opposite directions on admission of motive fluid to the ends of the piston chamber, and means controlled ointly by said valve and by said piston for venting one end of the piston chamber prior to the admission of motive fluid thereto and for prolonging the admission of motive fluid to the other end.

9, A fluid pressure-tool comprising a cylinder providing a piston chamber, a piston reeiprocable in said chamber and having an internal bore, the end Wall of said here forming a pressure area for driving the piston :torwardly, a tixed member extending axially into said piston chamber and into said bore to admit motive fluid continuously to said area, said member having a reduced portion to per:

mit motive fluid to pass from said here to the adjacent end of the chamber to be effective against the rear end of the piston, piston eonti'olled means for admit-ting motive fluid to the front end of the chamber to be effective againstthe front end of thepiston for the return stroke of the latter, a valve, said valve being shifted in opposite directions on admission of motive fluid to the ends of the piston chamber, and means controlled ointly by sa id valve and by said piston for venting one end of the piston ehaml'ier prior to the admission of motive fluid thereto and 'lor prolonging; the admission of motive fluid to the other enih said means being operative in one position of the valve and inoperative in another position of the valve.

Signed by me at Detroit, liliehigan this 27 day of July 1926.

EDXVARD W. S EVENS.

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